Search results for " Sensor."
showing 10 items of 1700 documents
Ultrasonic tomographic analysis for getting information on the mechanical structure of ceramic tiles
2009
Development and analysis of a model based on chirped fiber Bragg gratings employed for cracks characterization in materials
2018
In this work a model was developed that allows to understand the behavior of a chirped fiber Bragg grating for the detection and characterization of cracks in materials. In addition to the amplitude response, we show that the group delay of the grating provides useful information for the characterization of the crack. The position of the crack can be determined thanks to the linear chirp of the grating that fixes a correlation between the spatial position and both, the wavelength and the group delay. However, our analysis shows that this simple approach has a source of error, which can be overcome if a controllable external strain can be applied to the embedded grating, additional to the st…
The Experimental Validation of a New Thermodynamic Method for TDC Determination
2007
In-cylinder pressure analysis is becoming more and more important both for research and development purpose and for control and diagnosis of internal combustion engines; directly measured by means of a combustion chamber pressure transducers or evaluated by analysing instantaneous engine speed [1,2,3,4], incylinder pressure allows the evaluation of indicated mean effective pressure (IMEP), combustion heat release, combustion phase, friction pressure, etc...It is well known to internal combustion engine researchers that for a right evaluation of these quantities the exact determination of Top Dead Centre (TDC) is of vital importance: a 1° error on TDC determination can lead to evaluation err…
Influence of cavity preparation technique (rotary vs. ultrasonic) on microleakage and marginal fit of six end-root filling materials
2010
Objectives: To evaluate in vitro the effect of cavity preparation with microburs and diamond-coated ultrasonic tips on the microleakage and marginal fit of six end-root filling materials. Study Design. The following materials were assessed: amalgam (Amalcap), zinc oxide eugenol (IRM), glass ionomer (Vitrebond), compomer (Cavalite), mineral particle aggregate (MTA) and composite (Clearfil). Cavity preparation was performed with microburs or diamond ultrasonic tips in single-root teeth. The seal was evaluated in two experiments: a microleakage assay on the passage of dye to the interface; and a scanning electron microscopy study and analysis of epoxy resin replicas, measuring the size of gaps…
RFID epidermal sensor including hydrogel membranes for wound monitoring and healing
2015
This contribution experimentally demonstrates for the first time the feasibility of joint application of passive UHF RFID technology and hydrogel membranes to fabricate smart plasters able to gather and remotely transmit information on the conditions of human skin. In particular, this intelligent plaster is sensitive to temperature and fluid uptake/release and could open interesting scenarios in wound healing monitoring and drug delivery.
Strain-controlled domain wall injection into nanowires for sensor applications
2021
We investigate experimentally the effects of externally applied strain on the injection of 180$^\circ$ domain walls (DW) from a nucleation pad into magnetic nanowires, as typically used for DW-based sensors. In our study the strain, generated by substrate bending, induces in the material a uniaxial anisotropy due to magnetoelastic coupling. To compare the strain effects, $Co_{40}Fe_{40}B_{20}$, $Ni$ and $Ni_{82}Fe_{18}$ samples with in-plane magnetization and different magnetoelastic coupling are deposited. In these samples, we measure the magnetic field required for the injection of a DW, by imaging differential contrast in a magneto-optical Kerr microscope. We find that strain increases t…
Numerical analysis of the influence of ultrasonic vibration on crystallization processes
2011
The challenge in the future fabrication of semiconductor bulk crystals is the improvement of the crystal quality with a simultaneous increase of the yield. For that, a proper control of mass transfer within the fluid phase is required. Besides the damping of violent convective fluctuations, the thickness of the diffusion boundary layer, causing morphological instability, has to be decreased. The influence of ultrasound in molten Germanium was analyzed by numerical simulations. The simulations were provided by applying commercial software packages ANSYS ® and FLUENT ® . ANSYS ® was used to model the ultrasonic wave propagation in the whole growth system consisting of melt and crystal, crucib…
Ascorbic Acid determination using linear sweep voltammetry on flexible electrode modified with gold nanoparticles and reduced graphene oxide
2020
Indium tin oxide (ITO) coated on flexible polyethylene terephthalate (PET) substrate electrode was modified with reduced graphene oxide and gold nanoparticles by simple co-electrodeposition performed at -0.8 V vs SCE for 200 s. All samples were characterized by electron scan microscopy. The as prepared electrode was used as electrochemical sensor to selective detection of ascorbic acid using linear sweep voltammetry. Excellent results were obtained in a linear range from 20 to 150 µM of ascorbic acid with a limit of detection of about 3.1 µM (S/N=3.3). The sensors have a reproducibility of about 5.5% and also show high selectivity towards different interferents such as chlorine, calcium, ma…
A novel multi-wavelength procedure for blood pressure estimation using opto-physiological sensor at peripheral arteries and capillaries
2018
© 2018 SPIE. In this study, the Carelight multi-wavelength opto-electronic patch sensor (OEPS) was adopted to assess the effectiveness of a new approach for estimating the systolic blood pressure (SBP) through the changes in the morphology of the OEPS signal. Specifically, the SBP was estimated by changing the pressure exerted on an inflatable cuff placed around the left upper arm. Pressure acquisitions were performed both with gold standard (i.e. electronic sphygmomanometer), and Carelight sensor (experimental procedure), on subjects from a multiethnic cohort (aged 28 ± 7). The OEPS sensor was applied together with a manual inflatable cuff, going slightly above the level of the SBP with in…
SnO2 : Sb - A new material for high-temperature MEMS heater applications: Performance and limitations
2007
MEMS micro heater devices capable of long-term operation at temperatures up to 1000 degrees C are presented. The enhanced long-term stability has been achieved by employing antimony-doped tin oxide (SnO2:Sb) as a substitute for the conventionally used noble metal heater resistors. A detailed investigation of its high-temperature stability reveals that degradation is caused by out-diffusion of Sb impurities from the SnO2 film. (c) 2007 Elsevier B.V. All rights reserved.